Single bore multiple anchor (SBMA) are ground anchors with multiple strands, each bonded to the soil/rock and carrying a load.
A stable borehole is executed to the right diameter and designed length, filled with cement grout and then the multiple anchor strands grouted at different length within the single bore. By stressing each of the strands in turn the overall, capacity of the multiple strands is significantly increased over a single anchor of the same length.
Keller has been installing anchors for many years and patented the SBMA system. We have continually evolved the technique to achieve better performance. Testing and monitoring ensures high quality execution.